Electrically operated safety lock for doors

ABSTRACT

An electrically operated door lock comprising a housing adapted to be installed in the threshold of a door and a lock operating mechanism mounted in the housing. The lock operating mechanism includes a base member secured to the bottom of the housing, a top plate secured to the upper edge of the housing and two parallel rods extending between the top plate and the base member. A plate carrying a locking pin is slidably mounted on the two rods and has a screw threaded bore therein for receiving a screw threaded shaft which is rotatably mounted in the top plate and the base member. The shaft is rotated by a motor also mounted in the housing.

United States Patent [1 1 Belanger ELECTRICALLY OPERATED SAFETY LOCK FOR DOORS Raymond Belanger, Longueuil, Quebec, Canada Inventor:

Sogever Limitee, Quebec, Canada July 12, 1971 Assignee:

Filed:

Appl. No.2

References Cited UNITED STATES PATENTS 8/1913 Gardemeyer 292/155 8/1966 Ennitt 70/277 Primary Examiner--Albert G. Craig, Jr. An0rney-Raymond A. Robic [57] ABSTRACT An electrically operated door lock comprising a housing adapted to be installed in the threshold of a door and a lock operating mechanism mounted in the housing. The lock operating mechanism includes a base member secured to the bottom of the housing, a top plate secured to the upper edge of the housing and two parallel rods extending between the top plate and the base member. A plate carrying a locking pin is slidably mounted on the two rods and has a screw threaded bore therein for receiving a screw threaded shaft which is rotatably mounted in the top plate and the base member. The shaft is rotated by a motor also mounted in the housing.

7 Claims, 6 Drawing Figures mmmmza m s. 161.240 SHEET 10F 3 //VV[/Vf0/? Raymond BELA NGfR ATTORNEY I Pmmcunuza ma 3.767240 .SHEET 2 OF 3 Raymond BELA/V I? ELECTRICALILY OPERATED SAFETY LOCK FOR DOORS This invention relates to an electrically operated door lock of the type which may be used for locking the doors of banks or other commercial buildings.

It is a common practice to use manually operated locks for locking doors. Electrically operated door locks have been used in apartment buildings to unlock downstair doors from a higher floor location or from a distant area from the door. However, such locks are usually solenoid operated and may not be used to lock the normally heavy doors of banks and commercial buildings.

It is therefore the object of the present invention to provide a lock mechanism which is strong enough to resist the stress imposed on them by the weight of the heavy doors of commercial buildings.

The door lock mechanism, in accordance with the invention, comprises a housing adapted to be installed in the threshold of a door and a lock operating mechanism mounted in the housing. The lock operating mechanism includes a base member secured to the bottom of the housing, a top plate secured to the upper edge of the housing and two parallel rods extending between the top plate and the base member. A plate carrying a locking pin is slidably mounted on the two rods and has a screw threaded bore therein for receiving a screw threaded shaft rotatably mounted on the top plate and the base member. The above shaft is operated by a motor also positioned in the housing; 7

The motor drives the above-mentioned shaft through an endless screw and a worm gear secured to the shaft and coupled with the endless screw.

Limit switches are mounted on the inside wall of the housing and the plate carries a cam for operating the limit switches at the end of travel of the locking pin for stopping the motor.

The housing containing the door lock mechanism is removably installed in the threshold of the door and, for permitting easy removal of the lock for repairs, a terminal box is placed adjacent to the housing for permitting disconnection the leads of themotor and of the limit switches.

An electrical circuit is provided at a point adjacent or remote from the lock operating mechanism for operating the motor in both directions. The motor may be a reversible d.c. motor in which the direction of rotation is controlled by reversing the polarity of the d.c. voltage applied thereto. For that purpose, the electrical circuit may comprise two relays selectively energized by a double throw switch, such relay having contacts arranged to reverse the polarity of the voltage applied to the d.c. motor.

The invention will now be disclosed with reference to a preferred embodiment thereof and to the accompanying drawings in which:

FIG. 1 illustrates a heavy door with a lock, in accordance with the invention, installed in the threshold thereof;

FIG. 2 illustrates a perspective view of the lock in accordance with the invention;

FIG. 3 illustrates a section through the housing of the lock and through the threshold of the door for the-purpose of showing the lock in position;

FIG. 4 illustrates a section through the lock operating mechanism;

I operating mechanism; and

I FIG. 6 illustrates a schematic diagram of 'a suitable circuit for reversing the polarity of the motor driving the door lock.

Referring to FIGS. 1 to 5 of the drawings, there is disclosed a door lock mechanism 1.6 which is adapted to be positioned in a housing 12 placed in the threshold 13 of a door 14. The door lock mechanism comprises a base member 16 secured to the bottom of housing I2 through spacer l7, and a top plate 18 secured to a bracket 20 which is itself secured to the upper edge of the housing 12. Two rods 22 extend from the base member I6 to top plate 18 for guiding a plate 2 -6 which has a screw threaded bore therein. A screw threaded shaft 26 is rotatably mounted in base plate 16 and top plate 18 and rotation thereof in either direction causes the up and down movement of plate 24. A locking pin 28 is secured to plate 24 by screw 30 and follows the movement of the plate 24. Such locking pin 28 engages a hole 32 in the door 14 to lock the door.

The screw threaded shaft 26 is operated by a motor 34 which drives an endless screw 36 which is coupled to a worm gear 38 mounted on the shaft 26. One of the end bells 40 of the motor is made integral with base member 16 to facilitate mounting of the motor 34.

Referring more particularly to FIG. 4, it will be seen that shaft 26 is mounted on plate 16 at one end by means of a bearing 42. The other end of shaft 26 carries a pin 44 which is rotatably mounted in a sleeve 46 forming part of the base member 16. The shaft 26 has a flange 48 integral therewith to which is secured worm gear 38. Worm gear 38 is secured to flange 48 of shaft 26 through bolts 50 and a ring 52 is positioned between the flange 48 and the worm gear 38 at the location of the bolts.

Referring more particularly to FIGS. 2 and 3, plate 24 has an extension 54 secured thereto by screws 56. Such an extension carries a cam 58 for operating two limit switches 60 and 62 secured to the wall of the housing 12. Limit switches 66 and 62 are for stopping the operation of the motor 34 when the locking pin is respectively in locking position or fully retracted as it will be disclosed later in the description.

The leads 64 of the limit switches as well as the leads 66 of the motor are lead outside the housing through a connector 68 in a conventional manner. The connector has an insulating sleeve 70 maintained in position by threaded ring 72.

In order to prevent dust from penetrating inside the housing 12, such housing is closed by a cover 74 which is secured to the housing by screws 76.

Referring to FIG. 6, there is disclosed a suitable circuit diagram for operating motor 34 which, in the embodiment disclosed, is a reversible d.c. motor operated from a d.c. source. The circuit diagram comprises two relays R1 and R2 which may be selectively operated for controlling the rotation of motor 34 in one direction or the other depending on the polarity of the voltage supplied thereto. The circuit diagram also illustrates a double throw switch 78 which may be operated to the right for energizing the relay R1 through normally closed contacts R24. The operation of the relay RI closes contacts R1-2 and Rl-3 for applying a positive potential to the right hand terminal of motor 3 thus causing ble throw switch '78 is operated to the left, relay R2 is energized through contacts Rl-l. The operation of relay R2 closes contact R2-2 and R2-3 for applying a positive potential to the left hand terminal of motor 34, thus causing the rotation of the motor in the opposite direction.

Limit switches 60 and 62 mentioned previously in the description of the door lock operating mechanism are for deenergizing motor 34 when the locking pin 28 has reached its limit of travel in one direction of the other. The opening of limit switches 60 and 62 remove ground from relays R1 and R2 to deenergize such relays and so open their associated contacts to remove potential from the terminals of the motor 34.

A pilot lamp 80 is provided for indicating that the lock is ready for operation.

in order to permit easy removal of the door lock mechanism for repair, a terminal box 82 illustrated schematically in FIG. 6 is positioned adjacent to the housing 12. As commonly known the leads of the wiring diagram terminate at such terminal box and the leads of the motor and of the limit switches may be connected to the leads of the wiring diagram by conventional quick-connect connectors.

Although the invention has been disclosed with reference to a preferred embodiment thereof, it is to be understood that various modifications may be made to such embodiment without departing from the scope of the present invention.

1 claim 1. An electrically operates door lock comprising:

a. a housing adapted to be installed in the threshold of a door;

b. a lock operating mechanism mounted in said housing, said lock operating mechanism including a base member secured to the bottom of the housing, a top plate secured to the upper edge of the housing and two parallel rods interconnecting said top plate and said base member;

c. a plate carrying a locking pin slidably mounted on said two rods and having a screw threaded bore therein;

d. a screw threaded shaft rotatably mounted in said top plate and said base member and engaging the screw threaded bore of said plate; and

e. means for driving said screw threaded shaft for sliding said plate and thus operate such locking pin.

2. An electrically operated door lock as defined in claim 1, wherein said means for driving said screw threaded shaft includes a motor mounted on said base member, an endless screw driven by said motor, and a worm gear secured to said screw threaded shaft and coupled with said endless screw.

3. An electrically operated door lock as defined in claim 2, further comprising limit switches mounted on the inside wall of said housing, and wherein said plate carries a cam for operating said limit switches at the end of travel of said locking pin for stopping said motor.

4. An electrically operated door lock as defined in claim 3, wherein said housing is removably installed in the threshold of the door and further comprising a terminal box adjacent to the housing for disconnecting the lead of the motor and of the limit switches when the door lock is to be removed for repairs.

5. An electrically operated door lock mechanism as defined in claim 2, wherein said motor is a reversible d.c. motor and further comprising an electrical circuit for operating said motor in both directions by reversing the polarity of the d.c. voltage applied thereto.

6. An electrically operated door lock mechanism as defined in claim 5, wherein said electrical circuit comprises two relays selectively energized by a double throw switch, said relays having contacts arranged to reverse the polarity of the voltage applied to said d.c. motor.

7. An electrically operated door lock mechanism as defined in claim 5, further comprising a pilot lamp energized through said electrical circuit for indicating that the lock is ready for operation. 

1. An electrically operates door lock comprising: a. a housing adapted to be installed in the threshold of a door; b. a lock operating mechanism mounted in said housing, said lock operating mechanism including a base member secured to the bottom of the housing, a top plate secured to the upper edge of the housing and two parallel rods interconnecting said top plate and said base member; c. a plate carrying a locking pin slidably mounted on said two rods and having a screw threaded bore therein; d. a screw threaded shaft rotatably mounted in said top plate and said base member and engaging the screw threaded bore of said plate; and e. means for driving said screw threaded shaft for sliding said plate and thus operate such locking pin.
 2. An electrically operated door lock as defined in claim 1, wherein said means for driving said screw threaded shaft includes a motor mounted on said base member, an endless screw driven by said motor, and a worm gear secured to said screw threaded shaft and coupled with said endless screw.
 3. An electrically operated door lock as defined in claim 2, further comprising limit switches mounted on the inside wall of said housing, and wherein said plate carries a cam for operating said limit switches at the end of travel of said locking pin for stopping said motor.
 4. An electrically operated door lock as defined in claim 3, wherein said housing is removably installed in the threshold of the door and further comprising a terminal box adjacent to the housing for disconnecting the lead of the motor and of the limit switches when the door lock is to be removed for repairs.
 5. An electrically operated door lock mechanism as defined in claim 2, wherein said motor is a reversible d.c. motor and further comprising an electrical circuit for operating said motor in both directions by reversing the polarity of the d.c. voltage applied thereto.
 6. An electrically operated door lock mechanism as defined in claim 5, wherein said electrical circuit comprises two relays selectively energized by a double throw switch, said relays having contacts arranged to reverse the polarity of the voltage applied to said d.c. motor.
 7. An electrically operated door lock mechanism as defined in claim 5, further comprising a pilot lamp energized through said electrical circuit for indicating that the lock is ready for operation. 